/**************************************************************************** ** ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the QtScript module of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** No Commercial Usage ** This file contains pre-release code and may not be distributed. ** You may use this file in accordance with the terms and conditions ** contained in the Technology Preview License Agreement accompanying ** this package. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain additional ** rights. These rights are described in the Nokia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** ** ** ** ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ #ifndef QT_NO_QOBJECT #include "qscriptable.h" #ifndef QT_NO_SCRIPT #include "qscriptable_p.h" #include "qscriptengine.h" #include "qscriptcontext.h" #include "qscriptvalue.h" QT_BEGIN_NAMESPACE /*! \since 4.3 \class QScriptable \brief The QScriptable class provides access to the Qt Script environment from Qt C++ member functions. \ingroup script \mainclass With QScriptEngine::newQObject(), you can expose the signals and slots and properties of any QObject (or subclass) to script code. QScriptable augments this functionality by giving your C++ members access to the Qt Script environment they are invoked in; conceptually, it is similar to QObject::sender(). By subclassing QScriptable, you get the following functions in your class: thisObject(), argumentCount(), argument(), context() and engine(). With these functions, you have full access to the Qt Script environment from the slots and property access functions of your class, when they are invoked from script code. For example, you can throw a Qt Script exception from a slot; manipulate the `this' object associated with the function call; inspect the arguments stored in the QScriptContext to know the "real" arguments passed to the function from script code; and call script functions from your slot. A typical use case of QScriptable is to implement prototype objects for custom C++ types. You define the scriptable interface of your custom type in a QScriptable subclass using properties and slots; then you wrap an instance of your class using QScriptEngine::newQObject(), and finally pass the result to QScriptEngine::setDefaultPrototype(). See the \l{Default Prototypes Example} to see how this can be done. The following is what subclassing QScriptable typically looks like: \snippet doc/src/snippets/code/src_script_qscriptable.cpp 0 The only difference from regular QObject subclassing is that you also inherit from QScriptable. In the implementation of your slots, you can then use the functions inherited from QScriptable: \snippet doc/src/snippets/code/src_script_qscriptable.cpp 1 \sa {Default Prototypes Example}, QScriptEngine::newFunction() */ /*! \internal */ QScriptable::QScriptable() : d_ptr(new QScriptablePrivate()) { d_ptr->q_ptr = this; } /*! \internal */ QScriptable::~QScriptable() { delete d_ptr; d_ptr = 0; } /*! Returns a pointer to the QScriptEngine associated with the current Qt function call, or 0 if the Qt function was not invoked from script code. */ QScriptEngine *QScriptable::engine() const { Q_D(const QScriptable); return d->engine; } /*! Returns a pointer to the QScriptContext associated with the current Qt function call, or 0 if the Qt function was not invoked from script code. */ QScriptContext *QScriptable::context() const { if (QScriptEngine *e = engine()) return e->currentContext(); return 0; } /*! Returns the `this' object associated with the current Qt function call, or an invalid QScriptValue if the Qt function was not invoked from script code. */ QScriptValue QScriptable::thisObject() const { if (QScriptContext *c = context()) return c->thisObject(); return QScriptValue(); } /*! Returns the number of arguments passed to the function in this invocation, or -1 if the Qt function was not invoked from script code. \sa argument() */ int QScriptable::argumentCount() const { if (QScriptContext *c = context()) return c->argumentCount(); return -1; } /*! Returns the function argument at the given \a index, or an invalid QScriptValue if the Qt function was not invoked from script code. \sa argumentCount() */ QScriptValue QScriptable::argument(int index) const { if (QScriptContext *c = context()) return c->argument(index); return QScriptValue(); } #endif // QT_NO_SCRIPT #endif // QT_NO_QOBJECT QT_END_NAMESPACE